Why is January hotter then July in australila?

Hotter by temperature in degrees, yes, but 25 degrees in Japan with a very high humidity can certainly feel like 35 degrees in Australia with low humidity.

Answer Parts of Australia get 35 degrees, with high humidity. In general, Australia is very much hotter than Japan, but it helps to compare parts of Australia with various islands or cities in Japan. Okinawa is sub-tropcal, like much of Australia, but Australia has no equivalent to say Hokkaido.